Mechanics that Mutate (Or... Rule Changes as Consequence)

 Rules don’t have to be static. When mechanics shift over time, they make the world feel alive - magic grows unstable, weapons jam more often, travel gets harder as the map collapses. But mutation of rules should never be arbitrary. If players can’t trust the rules, they can’t trust the game. The change must follow from the fiction: corruption spreads, technology decays, seasons turn. When the rules bend because the world bends, players see growth, consequence, and escalation. They know the ground is shifting - but they also know why. That trust is what makes mutation thrilling instead of frustrating.